Baki the Grappler (Grappler Baki). I had almost forgotten about that anime. I loved that one! Death Note, Code Geass, and Slayers might be a few more along with the ones above.

wow so many good anime's in this world.

with sci fi and gore  “In everyone there is a demon, but those who can embrace it, not as a curse but as a gift, can use it as the sword of the heavens, or the spear of hell itself.”